1. Field of the Invention
The present invention relates generally to conveyors and systems that provide for the automatic storage and retrieval of merchandise and, in particular, such conveyors as used in the storage and retrieval of refrigerated products.
2. Background of the Invention
Various systems are known in the art that provide for the storage and retrieval of products and, in particular, food goods. With food goods and, in particular, dairy products, after the product has been manufactured and packaged it is typically stored in a central refrigerated warehouse for ultimate selective shipment to retail establishments. In the case of milk, after it has been bottled the individual containers are packaged into cases and the cases are then stored in a refrigerated warehouse from which they are ultimately loaded onto trucks and delivered to grocery stores and the like. Typically, the storage facility will be on the same site at which the bottling occurs.
In current dairy operations, a standard case is used and the dairy bottles are also standardized in size so that, for example, four one-gallon bottles or six one-half gallon bottles fit within the confines of the case. Case loading equipment is well known in the art and is used to load the cases with the particular size bottle. Also, case stacking machines are well known in the art that provide for stacking of the cases, typically five or six levels high, wherein the cases are designed to nest within each other. Thus, after the loading and stacking procedures, the stack of cases are conveyed on a continuously driven conveyor to the storage area. In many such systems, the stacks of cases are delivered to the storage area on an in-feed conveyor that rims perpendicularly to a plurality of storage conveyors. Hydraulically operable gates or stop means are known to stop the progress of a stack of cases along the in-feed conveyor so that a loading means, also hydraulically operable, can be operated to push the case stack onto one of the plurality of accumulator or storage conveyors. Recognition means, such as paint coding, bar coding, or video visual recognition can be used to signal control means as to the contents of the case stack so that the stack can be loaded onto the desired accumulator conveyor.
The individual stacks are then moved along the accumulator conveyors to a discharge end thereof. An out-feed conveyor runs perpendicular to the discharge ends of the storage conveyors, onto which out-feed conveyor the stacks can be loaded for distribution thereof to a truck loading area for ultimate retail distribution. The discharging from the storage conveyors onto the out-feed conveyor can also be accomplished automatically through the use of the control means.
A problem with the prior art concerns the parallel storage conveyors. Continuously driven chain conveyors are known, however, such conveyors require the use of drive motors on the side thereof that prevent such conveyors from lying closely adjacent each other. In other words, space must be allowed between each of the storage conveyors which increases significantly the size of the storage room in which the conveyors are located. Storage room size is, however, desirably kept to a minimum where the storage area is a refrigerated space. Moreover, electric drive motors generate heat that further negatively impacts refrigeration costs. Ratchet type storage conveyors are known wherein each conveyor includes a plurality of hydraulic cylinders that operate gravity dogs. The gravity dogs directly contact the bottom of the case or object for moving it successively in a ratcheting motion from one end of the storage conveyor to the other. Such conveyors can lie directly next to each other as the drive means are contained centrally thereof and can minimize heat contribution as the compressor therefor can be located outside of the refrigerated space. However, the plurality of hydraulic cylinders that are needed for operation, can increase the cost of purchasing and maintaining such a storage conveyor system.
Accordingly, it would be desirable to have storage conveyor means that can lie directly next to each other and be driven in a manner that is inexpensive and reliable. Furthermore, in any such automated storage and retrieval system, it is always desirable to have further improvements in the efficiency and ease of control thereof. In particular, it is desirable to have a dairy storage system whereby lower volume products can be retrieved in an efficient manner.